Insulated coverings have been devised for various uses and are customarily comprised of outer fabric covers or shells secured together along their outer peripheral edges and containing some form of insulation sandwiched between the inner and outer layers. Generally, in designing an insulated covering which is to be used as a garment or sleeping bag an insulating material is employed which is readily compressible into a small space, for example, to permit its compact storage for hiking or camping purposes but should also possess the ability to loft or expand when spread out or worn, since the insulating characteristics of the covering are greatly enhanced by trapping large air spaces within and between the outer layers. On the other hand, utilization of materials, such as, down which possess high loft characteristics has presented certain problems from the standpoint of maintaining uniformity and thickness of the covering, or, in other words, to prevent undue shifting of the fill material into one section of the covering. For this reason, insulating coverings of the type referred to are generally quilted or formed into compartments so as to prevent movement or shifting of the insulating fill material. Typical of the quilted construction referred to are those set forth and described in my previously issued patents including U.S. Pat. Nos. 3,787,906 and 3,857,125 for sleeping bag constructions. In addition, my previously issued U.S. Pat. No. 3,805,720 for QUILTED CONSTRUCTION sets forth and describes an insulated covering in which a baffle layer is used in combination with an insulating material between inner and outer shell layers in order to form a compartmentalized covering specifically where the baffle layers extend in a somewhat zig-zag or V-shaped configuration and are joined to seam zones of the outer shell layer so as to form generally V-shaped tubes which may be filled with a resilient insulating fill material; for example, natural or artificial fibers, such as wool or polyester or materials, such as, duck down, goose down or the like.
Quilted constructions of the type referred to have generally achieved the desirable characteristics of a lightweight insulated covering which has a relatively high degree of compressibility to enable compact storage; yet in use will afford a substantial degree of expansion of loft. Nevertheless, it is highly desirable to minimize the number of steps required in the construction and assembly of insulated coverings in order to simplify their construction; also to reduce the effective volume and weight of insulating materials required while achieving the maximum degree of loft so as to provide for a covering which is lightweight and readily foldable or rolled into a small compact package.